Carmen Wong Ulrich, the president and co-founder of ALTA Wealth Management, told me: "People think that it's a good idea to pre-pay a mortgage and/or pay a mortgage off ASAP." What's wrong with that? "This advice comes from a previous couple of generations who had horrible interest rates on their mortgages—in the 1980s, the average mortgage interest rate was in the teens. Imagine—my dad, who had great credit, was paying 17% on his mortgage. That's expensive. Today, mortgage rates are at incredible lows—you should be in no rush."